This is the kind of picture that's in love with show biz, like, say, Annie Get Your Gun (1950). But it's not a musical; it's a baggy-ants comedy. There is no gratuitous song to goose the action. The film stays focused on Flik's efforts to recruit "tough bugs" to battle the grasshoppers. When Flik, in full hiking regalia, hitches a ride on a dandelion puff, he's got the same giddy combination of desperation, awkwardness, and grace that Buster Keaton had when he hung on to a hot-air balloon in The Balloonatic (1923). And the picture grows more gloriously Keatonesque as it goes along. Flik hits a juicy dump known as the City, and mistakes that aforementioned group of failed circus bugs for freelance warriors. They mistake him for a talent scout. The result is a series of delightful and hair-raising riffs on the military and theatrical definitions of "knocking 'em dead."

Lasseter has called this movie "truly an epic of miniature proportions." It's a spectacle with a cast of hundreds and one and a half dozen rounded characters. Because they keep their critters moving, the Pixar craftsmen minimize anything saccharine or homiletic. The circus bugs are comic action figures descended from Chaplin as well as Keaton. Their showcase sequences have the same Rube Goldberg blend of unpredictability and inevitability that Chaplin gave big-top catastrophes in The Circus (1928), particularly the botched circus act that results in the accidental burning of the ringmaster P.T. Flea (John Ratzenberger). In addition to Slim the walking stick (David Hyde Pierce), the troupe includes a decrepit magic act featuring an oracular praying mantis (Jonathan Harris) and his voluptuous gypsy-moth wife and assistant (Madeline Kahn), as well as a sadly mild animal act with a rhino beetle aptly named Dim (Brad Garrett) and a black widow spider (Bonnie Hunt). Also scuttling through are a couple of Hungarian pillbox acrobats, Tuck and Roll (Michael McShane), who look like 3-D graffiti and grumble in some Middle European form of jabberwocky. They connect to the primal roots of slapstick. So does a ladybug who happens to be an irascible macho man (Denis Leary), and a caterpillar named Heimlich (story supervisor Joe Ranft) who speaks as if he always has a leaf in his mouth -- a voice stuck somewhere between a gurgle and a yodel.

The Pixar team's supercharged enthusiasm acts as an aesthetic disinfectant even on characters who at first glance are too kitschy-koo, like Atta's kid sister Dot. She comes off as a little steam engine that can, thanks partly to Hayden Panettiere's piping vocal performance and partly to the Pixar team's own predilection for energetic myths-within-myths. Dot, Flik's biggest fan, is the ringleader of the Blueberries, an ant-colony variation on the Brownies. Their after-school pageant dramatizing what they predict will happen to the colony -- the visiting bugs will vanquish the grasshoppers -- is the film's comic high point. The Blueberries paint gore and good-guy casualties on their backdrop just to heighten the realism.

The youthful Pixar filmmakers are as confident and innovative as the Blueberries. Seventy years ago, when the talkies arrived, the silent comedians who are the Pixar artists' true mentors often couldn't adjust to the dense new world of picture and sound. But Lasseter and company are themselves the pioneers of a new digital age. Without peers in speed and audacity, they're willing to pivot a scene on any single tool in their arsenal, from the sudden burst of color in a gypsy moth's wings to the vertiginous shifts in perspective when Flik grabs on to that dandelion puff. In a sense everything in this film is mechanical, and everything in it is also personal. That's why it conjures such a wide range of emotion: The grasshoppers are risible when they drunkenly carouse around a cantina, repulsive when they plummet into the ants' stronghold.

Lasseter and Stanton and the rest of the animators and gagsmiths use the computer with staggering imaginative freedom. It's as if their collective unconscious were the hard drive. They may need to see a movie as an assemblage of interlocking parts in order to channel their bounding creative energy. Even more than Toy Story, A Bug's Life is that archetypal American creation -- a lyrical contraption.

A Bug's Life.
Directed by John Lasseter and Andrew Stanton. Written by Andrew Stanton, Donald McEnery, and Bob Shaw, from a story by Lasseter, Stanton, and Joe Ranft. With the voices of Dave Foley, Kevin Spacey, Julia Louis-Dreyfus, Denis Leary, David Hyde Pierce, Bonnie Hunt, Hayden Panettiere, and Phyllis Diller.